Brilliant! Absolutely brilliant! I enjoyed it a lot. Perfection of a crossover, it is!

tetetf chapter 1 . 3/11/2013

Father placed his hand on Severus' forehead now and he felt something viscous sliding off as though it had been suffocating him. "You will see all that was blinded to you before. If not for that Albus Dumbledore would have you trailing along after daintly parsed out secrets. Voldemort isn't the only one who keeps his servants at arm's length. Be strong, my son. Try what might anyone tell you, but Jesus was frightened, as well. He was younger than you are, yes, but fear never leaves those who are forced to endure. Even when Lucifer's officers are at your back, remember that only a few steps further lays God's embrace. And mine."

With that, Father disappeared, and Severus stared around. "But I don't even know your name!"

"But of course you do," a cold voice interrupts and Severus startles again, this time looking up into the cold, judgmental eyes of Albus Dumbledore. Snape recoiled from the discomforting hands he'd almost touched

Well that was an interesting take on how he arrived to say "don't kill me" -although I don't remember if we hear Dumbledore's reply in the movie or just in the book or not. In the movie the whole pensieve scene is missing a lot and seems very rushed to me.
Do we know that Eileen Prince was a Slytherin? I wasn't sure about that. But it would explain how Snape developed disdain for Gryffendor even prior to becoming a student.
I really feel like Dumbledore used Snape, capitalized on his guilt and kept him in the dark. Although obviously for his own good, in the event that Snape's cover was somehow compromised.
And I feel like Snape was someone who never had a chance to be a good person, just because of events that were out of his control. I do hope he ultimately found his salvation.

I think that this story has become my new favourite of yours. I wanted to just cry. So heartbreaking, and he has to live with his pain of losing Lily.

It's very interesting the whole Dumbledore and Tobias scenario. It was almost like the two personnas were blending into one. His real father, and his mentor, each having affected his life in different ways.